A major strength at UC Davis is translational research and the use of nonhuman primates for the study of human health and disease. UC Davis has recognized in vivo imaging as an area of dynamic potential in which imaging techniques can be applied across the translational and clinical spectrum, and has made such technologies and resources a priority. The goal of this proposal is to obtain support for a PET/CT hybrid imaging system dedicated solely for use in translational research studies with nonhuman primates. This imaging system will be located within an existing and highly successful service core with the necessary technical expertise at the California National Primate Research Center (CNPRC), and with all of the necessary space, infrastructure, support, and knowledge to oversee and conduct PET/CT imaging in nonhuman primates at the highest quality level. Many NIH-funded studies currently in progress and planned will benefit substantially from the availability of this essential imaging technology. Imaging is currently limited to a microPET system with a 22 cm bore size which restricts studies to very young animals or brain imaging in smaller animals. The studies this instrument will benefit spans stem/progenitor cell trafficking, gene-based therapies and regenerative medicine, to pulmonary disorders such as asthma, and infectious diseases such as AIDS. The system will be readily accessible to NIH-funded investigators nationally through established outreach efforts such as those in the NIH-supported Center for Fetal Monkey Gene Transfer for Heart, Lung, and Blood Diseases and Center of Excellence in Translational Human Stem Cell Research. Funds are requested for a commercial system (GE Healthcare Discovery STE 16 PET/CT) that provides a fusion of high- speed, high-resolution capabilities of computed tomography (CT) with the metabolic and molecular imaging capabilities of positron emission tomography (PET). This system was selected based on the detector material (BGO), the enhanced spatial resolution when compared to other systems, and features essential for imaging macaques in a variety of age groups (infant to gravid adults to aged). This system will provide the needed PET/CT imaging to address unique opportunities for NIH-funded investigators at UC Davis and nationally, and expand existing capabilities in translational research and in vivo imaging in nonhuman primates.